Lighting fixture



BLACKWELL LIGHTING FIXTURE Filed Dec, 16

Y "INVENTOR WILLIAM BLACKWELL FIGAL Q ATTORN EY Patented Dec. 1 15",1925.

UNlTED. s'r-A Es 1 5 PATENT ounce-.1

' WILLIAM-'1. 'nnnc'xwnnn', or WESTFIELD, NEW mnsEY, nss'mnon 'rowns'rnronom LAM? COMPANY, A conrona'rron or PENNSYLVANIA.

Application filed December, 1921. Serlal- Io. sea-m.

To all whom it i 'Be it known that I, WILLIAM T. BLAGK- ,WELL, a citizenof the United States, and a resident of Westfield, in the county ofUnion and State-of New Jersey, have invented a new andlusefulImprovement in Lighting- Fixtures, of which the following is a speciThis invention relate; to lighting fixtures a lighting unit whichis'subst-antially 'dust-- proof andvinwhich the light from a givensource may be reflected and tr'ansmittedwith a minimumamount of loss.

Another object is to provide adust proof unit having a globe in-which acertain per-" centage of the light'rays will .passfrom beneath the globeand illuminate at least a portion of the outer surface thereof;Asfurth'er object is to provide a lighting unit having a globe in'whicha portion of.

the light will be transmitted through the upper portion ofjthe globe andanother portion of the light will be reflected from thelower portion ofthe; unit'and transmitted through-the upper portion of the globe.

A still further ob ect is to provide a translucent globe of such contourthat it mag,-

. durin' the process of manufacture, be rea ily finished to serve as'adirect or as a semiindirect lighting un1t as desired.

The character of 1i hting units or an -eflicient light-distributingelement. and one which must incorporate a design which is pleasing tothe eye and which will be harmonious to indoor environments. Thegoal'sought in the production of such li hting fixtures. is, however, toprovide a g obe of a contour which-will not only give the ventionprovides a desirable article from a manufacturing standpoint while thecons' figuration of the globe in such embodiment permits a widedistribution of light with an extremely low surface brilliancy. a

Furthermore, the light source; ,in y be readily obscured from s1ght,w,hich is an ad fixtures commonly employed for indoor use demandgiven relation to the vantage when the unit is employed for eitherdlrector semi-indirect lighting. The manufacturlng advantages of this unitare, evident from the fact that a variation in the s le of unit producedis attained by a variat on of the coating applied to the globe. Thiscoating may be translucent by, the applica tion of a sprayed superficiallayer or it ma be opaque depending upon the type of unlt required. Wherea'highly interior surface is desirable .on the lower portion of theglobe,

it may be silvered in any well known manner. The outer side, if desired,may be provided with a layer of enamel. When a.

mirror reflector isprovided, the lower ortionof the 'globe may becorruga orribbed for the purpose of breaking up s ecular reflectionwhich wold have a ten ency to project the image of the light source onto.thewalls orceiling. ,In addition to the above mentioned fea tures,which are prerequisites of the latest development in il1u minationengmeering, the present invention provides a substantially dust-prooffixture, 111 which the bulb is con- .-veni"entlyaccessible forreplacement through an aperture in the lower end of the globe.

The upper portion of the globe may be provide with an aperture adaptedto be closed by'a fitter or husk in which is'. carried any desirablelighting element, preferably an electric incandescentbulb of the type.known in the trade as the mazda 0.

Lamps of the aforementionedcharacter are substantially pear-shaped andemploy, what is termed. a concentrated filament which gives a-highintensity of light. This filament or light source'is of com 7 rativelysma'll'area and is thus readily a, apted for disposition in a givenrelation to the globe.

The present invention takes advanta eiof this feature by so ositionin'the light source as to obtain t e most. e ective and. eflicient usethereof-by disposing "it in a peculiar configuration I of the globeemployed.

The invention will be more fully under:

vstood by reference to the accompanying drawings which show'oneembodiment thereof in which Fig. 1 is an elevational view of-the im-.'proved lighting fixture or unit partly in section;

is a fragmentary elevational view ofthe lower cover';

Fig. 3 is a fragmentary plan view showing a modification of the meansfor attaching.

the cover to the globe;

Fig. 4 is a-fragmentary view, partly in vertical section, of themodification shown in Fig. 3; and

' Fig. 5 is a fragmentary view showing a section through a portion ofthe flange on the lower cover and illustrating the engagement between acam surface on this flange and a lug on the lower portion of the globe.

The globe employed in this invention is provided with apertures at thelower and upper ends thereof, the formeraperture be-.

ing utilized for removing or replacing lamps. The lower aperture1s,----however,

adapted to be closed by a cap which. mam

pass through the flange and thus illumi-' nate'the outer surface ofthe-lower portion of the globe thereby enhancing its appearance. Theupper aperture is closed by a fitter orhusk in which may be carried anydesirable lighting element. These, elements when assembled comprise thelighting fixture or unit.

A fixture embodying the advantages above outlined may consistsubstantially ,of

the three parts mentioned above; namely,

a husk or fitter 1, a globe 5 and a cap or cover 6.. The husk may be ofany wellknown standard construction but as illustrated hereinit issimilar to that described and claimed in my 'copending applicationSerial No. 510,840 filed Oct. 27 1921, universal lighting fixture,assigned to the Westinghouse Lamp Company. This husk is adapted to carrya socket 7 capable ofreceiving a standard incandescent electric lamp 8.The husk is also provided withan eyelet 9- in which a chain may besecured for the purpose of suspending the fixture.

In order to obtain the advantages of efiicient illumination, as aboveset forth, the globe 5 is preferably constructed with an upper convexportion or wall 11. This Wall or upper portion is preferably composed oftransparent glass throughwhich the light rays may be directlytransmitted. The lower portion 12, disposed below a transverse planewhich is indicated by the dotted line 13, converges toward the verticalaxis of the lamp for a given portion of its length then curvesdownwardly, and terminates at a given distance from the vertical axialline of the lam. thereby noridi-ng a lower aperture 14 tlirough which abulb may be inserted or removed from the socket 7.

Although the upper portion of the globe is preferably made of clearglass, it is obvious that if desirable it may be made of a lightdifl'using material, or else it may be etched or even given asuperficial coating. The lower portion 12 may be treated in a variety ofways to provide varying degrees of reflection or it may be treated toproduce different degrees of diffusion.

Exceptionally good results have been obtained by providing the lowerportion 12 with an interior mirrored surface whereby a preponderance ofuseful rays are transmitted through the upper portion of the globe, thelower portion of which is especially shaped to efficiently directreflected light. The peculiar configuration of this globe will beappreciated by an inspection of Fig. 1 which shows a section thereoftaken substantially on a vertical plane, and it will be noted that thelight center which is on the dotted line 15 lies approximately in aplane intermediate the upper and lower ends of the lower portion 12 ofthe globe.

After a lamp has been suitably positioned in the globe 5, the cap orcover 6 is placed over the aperture 14 and the globe is thus completelyclosed preventing the entrance of dust or other foreign matter.

For the purpose of permitting light to be transmitted to the outersurface of the globe, the perimeter of the cap 6 is sufficiently greaterthan the perimeter of the lower end of the globe to provide an annularspace therearound. The. ca however, is provided with a flange 16 whicwhen the cap is in position, occupies the space above mentioned.

For the purpose of quickly and conveniently attaching and removing thecap the .lower portion of the lobe is provided with a plurality of lugs1 'and the cap is provided with a collar 18 in which are disposed aplurality 'of notches 19 of right angular form. The cap is attached tothe globe by positioning it with the lugs in line .with the notches andthen moving the cap toward the globe until the lugs pass to the end ofthe vertical portion of the notches after which the cap is slightlyrotated to bring the horizontal portion of a notch about each lug andthe cap is then permitted to seat thereon. A depression 21 is providedin the horizontal portion of the notch to prevent the accidentaldisplacement of the cover.

The lugs are illustrated as being integral with the globe and of thesame material but it is obvious that they may be made of a differentmaterial, as for instance a metal, and may be secured to the globe inthe proper positions. One way of securing such lugs to a globe mayconsist. the provision of an annulus having lugs attached thereto;

, this annulus may be so constructed,- as to of. the attaching means foran all-glass cap is shown in Figs. 3, 4 and 5, wherein the cap 6 isrovided with a doubleflange con- 4 firmly 'seatin sisting o :the flange16 and a reverse flange 22'thereby providing an annular recess 23. Theflange 22.is provided with aplurality of notchesv 24 to permit thepassage of the lugs 17 when the cap is'juxtaposed for attachment to theglobe. passed through the notches 24.- the cap is rotated slightly tobring the lugs beneath the flange 22 and the cap is thus supported by'the engagement of the flange 22-with the though this cover may uicklybe secured orbe removed from the g obe its connection .thereto ispractically dust-proof. If desirable a resilient packing 25, consistingof a ring of any suitable material, may be ,d'isposed between the loweredge of the globe vided on the flange 22 so that when the cap .6 isrotat'edthe flange 22 will cause the cam to enga e with the lug l7 andlift the cap. 6' there y bringing 4 firmly against -the packing 25. Thiselastic packing also I serves to permit a slight-variation in therelative positions of the globe occasioned by expansion and contractionof these partsduringt-he heating and cooling of the unit.

It hasbeen found that by disposing the light source 15 midway betweenthe u per "and lower ends of the lower portion 0 the globe a portion ofthe; light rays will be reflected and caused topass directly through theupper portionll of the. globe-and thus illuminate the wall and ceiling.Ajgreaterv percentageof the rays, however, will be 7 transmitteddirectly through the upper por- -tion of the globe onto the walls andceiling.

The cover 6 may have a reflecting surface of the -.same value as'thelower "portion of the globe and will serve to reflect; rays directlyupwardly through the wall 11. Part of the light rays reflected from'theinner surface of the cover 6 will be'tran smitted through the flange 16when the cover is made of a translucent material as, for instance, anopalescent glass. This transmission of the lightrays through the flangeprovides an illumination of the outer surface "of the globe. Whendesirable the bowl portion of the cover may be opaque and the When thelugs have .ing and commercial requireni ts.f v

said globe: being of flange 16 may be either clear glass or trans lucentand illumination of the outer ortionof the globe may be m a('le more or;esssin tense by a variation in the opacity ofj the flange- 16. Whereanindirect, -=fighting-.

fixture is required, the flange.,16 -mjayfbe o be made entirely. of anopaque material in. which case .a metal cap maylbe employed.

It will be appreciated that this invention;

proof and at the same time furnishes a con struction by means of'whichthe outer surface of the bowl thereof' may be illuminated -to a greateror lesser degree.

I or the inconvenience of manually support- It will be readilyunderstood that al-" ing heavy lamp parts. The cover is of comparativelylightweightand when associated with .the globe," is 1 adapted to providea "dust-proof connectio It will be readily seen that the unit; p0sessesg features essential to meet thedemands of e cicnt light-v It isobvious that many media ti structural variations may be practicing thisinvention aii stood that the invention emb'r modifications as comewithin t the. appended claims.

Whatis claimed is c campu l U I transparent material having its lowerportion coated to provide; an interior reflectinggsurfacewhereby lightrays arerdirected throughthe iipperportion o-f saidfglobe, an aperturein the said lower portion for the replacement of'bulbs, a

cover for said aperturehaving-a flange of 1 light-transmitting material,projections of light transmittin material for, attaching said" coverovert e aperture'jojf said globe with the said flangedisposedtherearound, .said flange being of suflicientjly greaterdiameter than said aperture to provide an appreciableflight-transmitting medium -to permit the emission of light raysto theexterior of the lower portion of said globe,

, 2. A lighting "unit comprising a globe having alioldeflsaidfglobe-beingof a trans- ,parent, material," having. lowerportion silverd. on the exterior sideckets adapted to-provide aninterior-"light efl'ect ing surface forf'therefiection "of light, raysfthrough said; 'vllppe'r ortion,-, an aperture in said lower ortionorthe're'placementof lamps, a bow sh'a" d "cap/having an interiorly.projecting ange of light-transmitting material, the interior diameter ofsaid made opaque by a coating or-fthe cap may and 75' provides'a unitwhich is substantially dust- I having an aperture therein, a cap forsaid aperture having an interiorly extending flange, lugs integral withsaid globe and disposed about the perimeter of said aperture forengagement with said flange to secure said cap over the aperture, saidcap being of a sufliciently greater diameter than the "aperture toprovide a flange there around, sa id flange being of a lighttransmitting material.

4. A lighting unit comprising a globe having an aperture therein, a capfor said aperture, said cap having an interiorly extending flangeprovided with a collar adapted to enter said aperture, lugs integralwith said globe for engagement with said collar to secure said cap oversaid aperture, said cap being of a light transmitting material and of adiameter sufliciently greater than said aperture to provide a flangetherearound.

5. A lighting unit comprising a globe having an aperturetherein, aplurality of projections integral with the globe and disposed about saidaperture, a bowl-shaped cover for said aperture having an interiorlyprojecting flangeprovided with a collar ada ted to enter the aperture, aplurality of s ots in said collar to receive said projections, saidcover being of a light transmitting material and of suificiently greaterdiameter than said aperture to provide a flange there- I around.

6. A lighting unit comprisin a globe having an aperture therein, lugsintegral with said globe and disposed radially about the perimeter ofsaid aperture, a concave cover of a light transmitting material having"an interiorly projecting flange, a collar integral with and disposedabout the inner perimeter of said flange and slots in said collar toreceive lugs for securing the cover over said aperture, said cover beingof sufficiently greater diameter than said aperture to provide a collartherearound for the transmission oflight reflectedfrom .the innersurface of said cover.

7. A lighting unit comprising a globe having a light transmitting upperportion and a light reflecting lower portion, an aperture in said lowerportion, a cover for said aperture, said cover being of a greaterdiameter than said aperture and having an interiorly projecting flange,a collar integral .with said flange and adapted to enter the aperture ofsaid globe, light-transmitting means for securing said collar to theglobe with said flange disposed about the perimeter of said aperture toprovide for the transmission of light through the flange to the outersurface of said globe.

8. A lighting unit comprising a globe having an aperture in the upperportion thereof, a globe supporting member for closing said aperture, anaperture in the lower portion of saidglobe for the replacement of lampsand a bowl-shaped cover for said lower aperture, 'an, interiorlyextending flange integral with said cover, a collar integralwith anddisposed about the inner perimeter of said flange and adapted to enterthe aperture of said globe, light transmitting. means for securing saidcollar to said globe so as to dispose said flange about said aperture topermit the transmission of light rays through the outer surface of saidglobe.

9. A lighting unit comprising a globe having a light transmitting upperportion and a light reflecting lower portion, an aperture in said upperportion, a globe supporting member for closing said aperture, anaperture in said lower-portion for the replacement of lamps and a coverforsaid lower aperture, said cover having an interiorly extending flangeprovided with a collar adapted to enter the aperture of said lowerportion of the globe, whereby said flange may be disposed about theperimeter of said aperture to permit the transmission of light rays tothe outer surface of the lower portion of said globe and lighttransmitting means for securing said collar to said globe, the diameterof said cover being sufl'iciently greater than said lower aperture forthe purpose of providing a flange thercaround.

10. A lighting unit comprising a globe havingupper and lower portions ofdifferent coefficients of light absorption, an aperture in said upperportion, a globe supporting member for closing said aperture, anaperture in said lower portion for the replacement of lamps and a coverfor said lower aperture having a diameter sufliciently greater than saidaperture to provide a flange around the end of the said lower portion ofthe globe, means for attaching said cover to said globe, said means andsaid flange being of a light transmitting material for the purpose ofpermitting light rays to,

juxtaposed with relation to said globe, whereby said cover may beslightly moved about its vertical axis and supported on said lugs andpositioned to provide a flange about thelower aperture and means forpreventing accidental removal of said cover.

12. A lighting unit comprising a globe having an aperture in the upperend thereof and a husk adapted to close said aperture, an aperture inthe lower end of said globe, a plurality of lugs upon the inner side'ofthe lower end of said globe, a cover having an interiorly extendingflange provided with .moved about its vertical axis notches for thepassage of said lugs .when said Cover is juxtaposed with relation tosaid globe, whereby saidcover may be slightly and supported on saidlugs, means'for preventing accidental removal of said cover and meansfor maintaining said cover in resilient engagement with said globe.

In testimony whereof I" have hereunto subscribed my name this 15th dayof Dec., 1921.

WVILLIAM T. BLAOKWELL.

